A Styrofoam packing material has been used for a long time for packing commodity and industrial products. Although the Styrofoam package material has a merit such as a good thermal insulation performance, it has also various disadvantages, i.e., recycling the Styrofoam is not possible, soot is produced when it burns, a flake or chip comes off when it is snagged because of it's brittleness, an expensive mold is needed for its production, and a relatively large warehouse is necessary to store it.
Therefore, to solve such problems above, other packing materials and methods have been proposed. One method is a fluid container (air-packing device) for sealingly containing a liquid or gas, typically an air as a cushion. An air-packing device has excellent characteristics to solve the problems in the Styrofoam. First, because the air-packing device is made of only thin films, it does not need a large warehouse to store it unless the air-packing device is inflated. Second, a mold is not necessary for its production because of its simple shape and structure. Third, the air-packing device will not produce a chip or dust which has adverse effect on precision products. Further, recyclable materials can be used for thermoplastic films of the air-packing device. Furthermore, the air-packing device can be produced with low cost.
FIG. 1 shows an example of air-packing device in the conventional technology. The air-packing device 10a is composed of first and second air-packing thermoplastic films 13 and 14, respectively, and a check valve 11. Typically, each thermoplastic film is composed of three layers of materials: polyethylene, nylon and polyethylene which are bonded together with appropriate adhesive. The nylon layer is incorporated to increase physical strength of the thermoplastic film. The first and second thermoplastic films are heat-sealed together around seal portions 12a, 12b after the check valve is attached. Thus, one container bag 10a sealed with the heat seal portions 12a, 12b is formed as shown in FIG. 1.
Air-packing devices are becoming more widespread because of the above noted advantages. Products to be enclosed by air-packing devices come in various shapes, sizes and materials. Moreover, a product having a simple shape can have a complicated shape when combined with other products. Generally, it is difficult and time consuming to pack a product that has irregular shapes or sizes in a container box. Two or more different types of air-packing devices of complicated structure may be necessary to firmly hold a product having a complicated shape. Moreover, it is not cost effective to manufacture specific air-packing devices tailored to fit to each unique product. Thus, there is a need for a cost effective air-packing system that can be applied to various products.